For those unfamiliar with the Urim and Thummim, I was thinking that a little background might help.
Urim comes from the Hebrew uwriym, which is the plural of uwr, meaning light, flame, or fire. Uwr is from the root word owr, which means: ‘to be or to make luminous; break of day; to give or show light; to be enlightened; to shine, or to set on fire.’
Urim literally means lights.
Thummim is from the Hebrew Tummiym, which is the plural of tom, meaning: ‘completeness; innocence; integrity; perfect, or uprightness.’ Tom is derived from the root word tamam, which means: ‘to complete in a [positive or negative] sense; to be perfect.’
Thummim literally means perfections or complete truth.
The words are translated various ways in different versions of scripture: ‘Lights and Perfections’ ‘Light and Truth’ ‘Manifestation and Truth’ and ‘The Sacred Lots.’
The Urim and Thummim represent counsel, guidance [to determine order of priests] decisions, to receive answers. The use of them were a right of the priesthood, to give counsel and direction from God. They also represent judgement.
(See Exodus 28:30)